MOS transistors may be formed with epitaxial source and drain regions which extend toward each other in the substrate, so that the source and drain regions have a minimum separation at stressor tips in the substrate at a depth of 40 to 70 nanometers below the gate dielectric layer. These MOS transistors may have leakage currents higher than a desired value, due to leakage currents between the source and drain at the minimum separation. Such leakage currents may be included in drain induced barrier lowering.